176 research outputs found

    Impact of metformin on the clinical and metabolic parameters of women with polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials

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    Context: Polycystic ovary syndrome (PCOS) is one of the commonest endocrine disorders affecting women of reproductive age, and metformin is a widely used medication in managing this condition. Aim: To review the available literature comprehensively on the therapeutic impact of metformin on the clinical and metabolic parameters of women with PCOS. Data source: We searched PubMed, MEDLINE, Scopus, Embase, Cochrane Library and the Web of Science and selected sources for grey literature from their inception to April 2020. An updated search in PubMed was performed in June 2022. Data synthesis: Two reviewers selected eligible studies and extracted data, and the review is reported following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: In 24 eligible randomised controlled trials (RCTs) involving 564 participants who received metformin therapy, metformin was associated with significant reduction in body weight by 3.13 kg (95% CI: −5.33, −0.93), body mass index (BMI) by 0.82 kg/m² (95% CI: −1.22, −0.41), fasting blood glucose [standardised mean difference (SMD): −0.23; 95% CI: −0.40, −0.06], low-density lipoprotein cholesterol (LDL-C) (SMD: −0.41; 95% CI: −0.85, 0.03), total testosterone (SMD: −0.33; 95% CI: −0.49, −0.17), androstenedione (SMD: −0.45; 95% CI: −0.70, −0.20), 17-hydroxyprogesterone (17-OHP) (SMD: −0.58; 95% CI: −1.16, 0.00) and increase the likelihood of clinical pregnancy rate [odds ratio (OR): 3.00; 95% CI: 1.95, 4.59] compared with placebo. Conclusion: In women with PCOS, metformin use has shown a positive impact in reducing body weight, BMI, total testosterone, androstenedione, 17-OHP, LDL-C, fasting blood glucose and increasing the likelihood of pregnancy in women with PCOS

    Assessment of critical parameters affecting the behaviour of bearing reinforced concrete walls under fire exposure

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    Purpose: This research paper aims to investigate reinforced concrete (RC) walls' behaviour under fire and identify the thermal and mechanical factors that affect their performance. Design/methodology/approach: A three-dimensional (3D) finite element (FE) model is developed to predict the response of RC walls under fire and is validated through experimental tests on RC wall specimens subjected to fire conditions. The numerical model incorporates temperature-dependent properties of the constituent materials. Moreover, the validated model was used in a parametric study to inspect the effect of the fire scenario, reinforcement concrete cover, reinforcement ratio and configuration, and wall thickness on the thermal and structural behaviour of the walls subjected to fire. Findings: The developed 3D FE model successfully predicted the response of experimentally tested RC walls under fire conditions. Results showed that the fire resistance of the walls was highly compromised under hydrocarbon fire. In addition, the minimum wall thickness specified by EC2 may not be sufficient to achieve the desired fire resistance under considered fire scenarios. Originality/value: There is limited research on the performance of RC walls exposed to fire scenarios. The study contributed to the current state-of-the-art research on the behaviour of RC walls of different concrete types exposed to fire loading, and it also identified the factors affecting the fire resistance of RC walls. This guides the consideration and optimisation of design parameters to improve RC walls performance in the event of a fire

    Shear strengthening of reinforced concrete beams using externally-bonded aluminum alloy plates: An experimental study

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    Citation: Jamal A. Abdalla, Adi S. Abu-Obeidah, Rami A. Hawileh, Hayder A. Rasheed, Shear strengthening of reinforced concrete beams using externally-bonded aluminum alloy plates: An experimental study, Construction and Building Materials, Volume 128, 15 December 2016, Pages 24-37 http://dx.doi.org/10.1016/j.conbuildmat.2016.10.071Recently developed high strength aluminum alloys (AA) have desirable characteristics that make them attractive as externally bonded strengthening materials. This paper investigates the potential of using AA plates for shear strengthening of reinforced concrete (RC) beams. Five shear deficient RC beams were externally strengthened using AA plates with different orientations. It is observed that the shear capacity of the strengthened beams has increased in the range of 24%–89% compared to the un-strengthened beam. Shear capacity of the strengthened beams was also predicted using the ACI440, FIB14, TR55 and SMCFT design guidelines with the later one giving the most accurate predictions

    Assessing the Prevalence and Potential Risks of Salmonella Infection Associated with Fresh Salad Vegetable Consumption in the United Arab Emirates

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    This study aimed to investigate the occurrence and characteristics of Salmonella isolates in salad vegetables in the United Arab Emirates (UAE). Out of 400 samples tested from retail, only 1.25% (95% confidence interval, 0.41–2.89) were found to be positive for Salmonella, all of which were from conventional local produce, presented at ambient temperature, and featured as loose items. The five Salmonella-positive samples were arugula (n = 3), dill (n = 1), and spinach (n = 1). The Salmonella isolates from the five samples were found to be pan-susceptible to a panel of 12 antimicrobials tested using a disc diffusion assay. Based on whole-genome sequencing (WGS) analysis, only two antimicrobial resistance genes were detected—one conferring resistance to aminoglycosides (aac(6′)-Iaa) and the other to fosfomycin (fosA7). WGS enabled the analysis of virulence determinants of the recovered Salmonella isolates from salad vegetables, revealing a range from 152 to 165 genes, collectively grouped under five categories, including secretion system, fimbrial adherence determinants, macrophage-inducible genes, magnesium uptake, and non-fimbrial adherence determinants. All isolates were found to possess genes associated with the type III secretion system (TTSS), encoded by Salmonella pathogenicity island-1 (SPI-1), but various genes associated with the second type III secretion system (TTSS-2), encoded by SPI-2, were absent in all isolates. Combining the mean prevalence of Salmonella with information regarding consumption in the UAE, an exposure of 0.0131 salmonellae consumed per person per day through transmission via salad vegetables was calculated. This exposure was used as an input in a beta-Poisson dose–response model, which estimated that there would be 10,584 cases of the Salmonella infection annually for the entire UAE population. In conclusion, salad vegetables sold in the UAE are generally safe for consumption regarding Salmonella occurrence, but occasional contamination is possible. The results of this study may be used for the future development of risk-based food safety surveillance systems in the UAE and to elaborate on the importance for producers, retailers, and consumers to follow good hygiene practices, particularly for raw food items such as leafy salad greens

    Sustainable use of palm oil fuel ash as a supplementary cementitious material: A comprehensive review

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    Cement concrete has been popularly used as a construction material with an approximate annual consumption of 10 billion tons. Increase in urbanization and industrialization increased the demand of concrete materials at recent days. It has been estimated that the cement industry alone generates approximately 6–7% of the total CO2 emissions. These environmental concerns demand the use of alternative renewable and sustainable materials to produce green concrete. Meanwhile, a large amount of agricultural waste, especially palm oil waste is disposed into the open area and landfills, causing serious environmental problems. An estimated 12 million tons of palm oil fuel ash (POFA) is generated in the world per annum. To minimize the passive effects of concrete production using traditional Portland cement, it was recommended by many researchers to adopt the palm oil waste fall-outs as a supplementary cementitious material. It may be considered a suitable and reliable source for better solutions to magnify the sustainability of the construction industry. This paper reviews the potential utilization of POFA as an alternative cementitious material in concrete. The impact of POFA on the fresh, hardened and durability properties of concrete are deliberated, providing a brief of the current knowing about a suitable utilization of POFA as SCM to promote a sustainable environment in the construction industry. The grinding treatment of raw POFA particles significantly enhances the quality of POFA in terms of compressive strength, resistance against aggressive environments and assist in reducing the drying shrinkage of concrete, although there is a tendency to increase the water absorption and delay the hydration heat of cement mortar. The high quantity of SiO2 in POFA enables pozzolanic reaction and delays the setting times with the addition of CaO to produce further C–S–H gels. The utilization of POFA (20%), ultrafine POFA and nano POFA (30%) can produce high strength and durable concrete, proving to be a promising contribution towards the sustainability of the construction industry

    Geopolymer concrete incorporating recycled aggregates: A comprehensive review

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    Several industrial by-products are extensively used again as a supplementary cementitious material or aggregates in the interest to reduce environmental footprints in terms of energy depletion, pollution, waste disposition, resource depletion, and global warming related with conventional cement. A remarkable quantity of industrial scrap materials, primarily designated as construction and demolition waste from the construction industry, has transformed into crucial apprehension of governments. In the recent past, substantial explorations have been accomplished to appreciate the distinct characteristics of concrete, employing recycled aggregates from construction and demolition waste. Geopolymer composite is a new cementitious material, and it appears to be a potential replacement for conventional cement concrete. This paper summarises the previous research concerning the utilisation of recycled aggregate as a partial or complete supplants for conventional aggregates in geopolymer concrete. The influence of recycled aggregate addition on the fresh and hardened properties of geopolymer concrete is comprehensively reviewed in this paper. The studies suggest significant improvement in the workability on addition of recycled aggregates to geopolymer concrete. However, the addition results in increased water absorption and sorptivity

    Clinical Profile of Mortality and Treatment Profile of Survival in Patients with COVID-19 Pneumonia Admitted to Dubai Hospital

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    Background: Most COVID-19 studies conclude old age and coexisting illnesses as mortality determinants owing to different populations or methodologies, or omitting factors affecting outcomes. Methods: We analyzed COVID-19 patients’ data (N = 391) of Dubai Hospital between January 1, 2020 and June 30, 2020. Results: Only 19 patients (4.8%) were UAE nationals, while 372 (95.2%) were expatriates. Median age was 48 (interquartile range, 40–56) years; 22% were <40 years, and only 16.6% were female. Cough was the most common symptom (78.7%), fever was 77.4%, and gastrointestinal symptoms were least common (13.8%). Approximately 95% had elevated C-reactive protein (CRP) and D-dimers (79%), lymphocytopenia 47.3%, and thrombocytopenia 13.8%. Mortality was 30% for the total sample and 50% in ICU patients. ICU patients were older than non-ICU (age; 49.6 ± 10.9 vs. 46.7 ± 12.7 years, p = 0.04). Eighty-five percent of ICU patients required invasive mechanical ventilation, 78% vasopressors, 88% sedation, 84% muscle paralysis, while none require any of these in the medical group. Survivors had fewer patients with sedatives (p = 0.01). The median length of stay in the hospital was 19 days, ICU stays 14 days, and ventilator 11 days. The Mann-Whitney test showed that survivors spent more days in the ICU (median [IQR] 18 [6.5–29.5] vs. 11 [4–18], p value 0.003) and the hospital (32 [14.5–49.5] vs. 14 [7–21], p value 0.001) than nonsurvivors. Ferritin and D-dimers were higher in nonsurvivors, but CRP was lower in nonsurvivors (ferritin (ng/mL) median (IQR) 1,434 (661.5–2206.5) versus 1,362 (630–2,094), p value = 0.017, CRP (mg/L) 118.7 (53.4–184) versus 134.9 (66.5–203.2), p value 0.001 and D-dimer (µg/mL) 1.54 (0–3.13) versus 1.09 (0–2.51), p value = 0.001). Multiple logistic regression analysis determined age, fever on admission, use of oxygen, mechanical ventilation, and steroids as predictors of survival. Conclusions: COVID-19 patients were young males with pre-existing conditions. Ferritin, CRP, and D-dimers were higher in nonsurvivors. Treatment with chloroquine, antivirals, and anticoagulation was not different between survivors and nonsurvivors. Steroid use was a survival predictor

    Evaluating the association of biallelic OGDHL variants with significant phenotypic heterogeneity

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    BACKGROUND: Biallelic variants in OGDHL, encoding part of the α-ketoglutarate dehydrogenase complex, have been associated with highly heterogeneous neurological and neurodevelopmental disorders. However, the validity of this association remains to be confirmed. A second OGDHL patient cohort was recruited to carefully assess the gene-disease relationship. METHODS: Using an unbiased genotype-first approach, we screened large, multiethnic aggregated sequencing datasets worldwide for biallelic OGDHL variants. We used CRISPR/Cas9 to generate zebrafish knockouts of ogdhl, ogdh paralogs, and dhtkd1 to investigate functional relationships and impact during development. Functional complementation with patient variant transcripts was conducted to systematically assess protein functionality as a readout for pathogenicity. RESULTS: A cohort of 14 individuals from 12 unrelated families exhibited highly variable clinical phenotypes, with the majority of them presenting at least one additional variant, potentially accounting for a blended phenotype and complicating phenotypic understanding. We also uncovered extreme clinical heterogeneity and high allele frequencies, occasionally incompatible with a fully penetrant recessive disorder. Human cDNA of previously described and new variants were tested in an ogdhl zebrafish knockout model, adding functional evidence for variant reclassification. We disclosed evidence of hypomorphic alleles as well as a loss-of-function variant without deleterious effects in zebrafish variant testing also showing discordant familial segregation, challenging the relationship of OGDHL as a conventional Mendelian gene. Going further, we uncovered evidence for a complex compensatory relationship among OGDH, OGDHL, and DHTKD1 isoenzymes that are associated with neurodevelopmental disorders and exhibit complex transcriptional compensation patterns with partial functional redundancy. CONCLUSIONS: Based on the results of genetic, clinical, and functional studies, we formed three hypotheses in which to frame observations: biallelic OGDHL variants lead to a highly variable monogenic disorder, variants in OGDHL are following a complex pattern of inheritance, or they may not be causative at all. Our study further highlights the continuing challenges of assessing the validity of reported disease-gene associations and effects of variants identified in these genes. This is particularly more complicated in making genetic diagnoses based on identification of variants in genes presenting a highly heterogenous phenotype such as "OGDHL-related disorders"

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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